Every cell in your body is surrounded by a biological ‘bag’ known as the cell membrane. Rather than being a solid structure, this membrane is much more fluid. It’s made from a thin layer of fatty molecules – including phospholipids and cholesterol – studded with important signalling proteins that transmit messages from outside to inside the cell. This image shows a computer model of one of these signallers, CXCR4, which is made of two separate parts. These halves need to pair up to work properly, wriggling their way through the membrane to find their partner. Researchers have used computer simulations of the physical properties of the membrane to discover that cholesterol acts as a kind of molecular 'glue', bringing the two parts of CXCR4 together properly. Faulty CXCR4 signals have been implicated in diseases such as cancer and AIDS, so understanding more about how it works could point towards better treatments.
Written by Kat Arney
BPoD stands for Biomedical Picture of the Day. Managed by the MRC London Institute of Medical Sciences the website aims to engage everyone, young and old, in the wonders of biomedicine. Images are kindly provided for inclusion on this website through the generosity of scientists across the globe.